Should paleoshorelines of ancient martian oceans be close to present-day equipotential surfaces?

Abstract

Thermal isostasy provides a link between surface elevation and thermal state of the lithosphere. Variations in martian surface heat flow, similar to those observed in terrestrial continental tectonothermally stable areas, could result in elevation differences of kilometric scale through differential thermal isostasy. This effect is enhanced with the increase of heat sources located within the crust. Local differences in the thermal history of the Mars’ lithosphere could have appreciably distorted the original long-avelength topography of putative martian paleoshorelines. This work hows that a paleoequipotential surface does not necessarily have to fit well a present-day equipotential surface, and that diverse processes, including thermal isostasy and operating throughout the martian history, must be taken into account when evaluating paleoshorelines through assessment of high-resolution topography.